This invention relates to a key for a lock apparatus.
A preferred form of the invention relates to a key used in a lock that is opened not only by use of the key but also by the manual entry of a combination.
Lock mechanisms incorporating both key operation and combination operation are old. An early patent to Raab, U.S. Pat. No. 1,389,380, shows a lock mechanism in which the combination or permutation mechanism needs to be operated to enable the lock to be opened by the key.
U.S. Pat. 1,937,523 to Machinist shows a lock in which the combination must be first dialed into the combination mechanism before a key can be inserted to open the lock.
A later version of the above locks is the one shown in U.S. Pat. No. 3,383,886 to Herman, in which the key is first inserted and then the combination dial operated to enable the key to be turned. Thereafter, the dial must be further turned in order to open the lock.
A more recent patent to Hutchins, U.S. Pat. No. 4,416,337, shows a lock mechanism having a key and a combination lock comprising three or more dials.
In German Patent No. 1,428,526, combination dials are first moved coded distances, and then a coded key is inserted to move the wheels further distances to effect opening of the lock.
The design of the German lock and key is such that the lock can be opened by differently coded keys, provided that the combination discs or dials are moved amounts related to the code of the particular key used.
U.S. Pat. No. 4,325,240 to Gable shows a lock much like the one in the German patent, but having the reverse sequence, i.e., the key is inserted first, and the coded combination is thereafter dialed in. The Gable patent, like the German patent, can be opened by differently coded keys provided that the combination dialed in is related to the particular key used.
It is evident from the above that in both the German patent and the Gable patent one stage of coded input is effected by rectilinear insertion of a flat coded key.
A main object of the present invention is to provide an improved key for a key/combination lock.
Another important object of the invention is to provide a uniquely shaped key for a key/combination lock so designed that a uniquely shaped key is required to open it, whereby duplication of the key is made difficult.
Another object of the invention is to provide a key of a unique cylindrical form, rather than flat form, as in the German and Gable patents, making it difficult to duplicate.
Another object of the invention is to provide a key/combination lock in which the turning movement of a key, rather than rectilinear movement, is utilized to effect one stage of coded movement of combination dials.
The present invention provides a key/combination lock in which two stages of movement of turnable elements are necessary to open the lock, one stage of movement being effected by insertion and turning of a key, while the second stage of movement is effected manually. The present invention also provides a cylindrical key for opening the above lock.
The lock of the present invention preferably incorporates a recording feature. That feature is per se not new, being shown, for instance in patents to Knistrom U.S. Pat. No. 1,253,051, De Vines U.S. Pat. No. 3,438,0-51 and U.S. Pat. No. Gable 4,325,240.
Another object of the invention is to provide a lock mechanism of the coded wheel type having a specially designed key which cannot only turn the wheels coded distances but also can actuate a recording mechanism.
A further object of the invention is to provide a lock and key arrangement as just recited above wherein there are sequencing means for controlling the sequence of operations to assure, among other things, that the lock cannot be unlocked without recording the identity of the key used to enter the lock.
A still further object is to provide a key for a lock of the type just recited above that participates in the sequencing operations.
The concept of recording the identity of the specific key used in opening a lock is ideal for the lock box industry in which a key container within the lock box is releasable upon proper operation of a series of coded wheels so as to enable the user to remove a stored "access" key from the container for use in gaining access to another structure.
It is another object of the invention to provide a lock box/key holder unit having a latch for releasably retaining a key container in place, an exterior release button for releasing said latch, a series of coded wheels preventing actuation of the button until the coded wheels have been turned to predetermined positions, a recording mechanism operable when actuated for recording predetermined positions of the coded wheels, and a sequencing means for preventing actuation of the button until the sequencing means has been actuated by a key, the sequencing means also participating in the actuation of the recording mechanism.
It is a still further object of the invention to provide a key which not only turns the coded wheels but also can actuate other decides in the lock and particularly to provide a key in which turning movement of the key turns coded wheels, but wherein the key by its design is permitted to subsequently move rectilinearly for actuating certain devices; and is also so formed as to be capable of resetting at least part of the sequencing mechanism as the key is retroturned.